Martin Luther King at Washington DC's Lincoln Memorial in 1968. Barack Obama used the day before his inauguration to honour the spirit of King. Photograph: Francis Miller/Getty

The civil right achievements of Martin Luther King are quite justly the focus of the annual birthday commemoration of his legacy. But it is remarkable, as I've noted before on this holiday, how completely his vehement anti-war advocacy is ignored when commemorating his life (just as his economic views are). By King's own description, his work against US violence and militarism, not only in Vietnam but generally, was central - indispensable - to his worldview and activism, yet it has been almost completely erased from how he is remembered.

King argued for the centrality of his anti-militarism advocacy most eloquently on April 4, 1967, at Riverside Church in New York City - exactly one year before the day he was murdered. That extraordinary speech was devoted to answering his critics who had been complaining that his anti-war activism was distracting from his civil rights work ("Peace and civil rights don't mix, they say. Aren't you hurting the cause of your people, they ask?"). King, citing seven independent reasons, was adamant that ending US militarism and imperialism was not merely a moral imperative in its own right, but a prerequisite to achieving any meaningful reforms in American domestic life.

In that speech, King called the US government "the greatest purveyor of violence in the world today", as well as the leading exponent of "the deadly Western arrogance that has poisoned the international atmosphere for so long" (is there any surprise this has been whitewashed from his legacy?). He emphasized that his condemnations extended far beyond the conflict in Southeast Asia: "the war in Vietnam is but a symptom of a far deeper malady within the American spirit." He insisted that no significant social problem - wealth inequality, gun violence, racial strife - could be resolved while the US remains "a nation that continues year after year to spend more money on military defense than on programs of social uplift" - a recipe, he said, for certain "spiritual death". For that reason, he argued, "it should be incandescently clear that no one who has any concern for the integrity and life of America today can ignore the present war." That's because:

"If America's soul becomes totally poisoned, part of the autopsy must read Vietnam. It can never be saved so long as it destroys the deepest hopes of men the world over."

Working against US imperialism was, he said, "the privilege and the burden of all of us who deem ourselves bound by allegiances and loyalties which are broader and deeper than nationalism and which go beyond our nation's self-defined goals and positions." For King, opposing US violence in the world was not optional but obligatory: "We are called to speak for the weak, for the voiceless, for victims of our nation and for those it calls enemy . . . ." The entire speech is indescribably compelling and its applicability to contemporary US behavior obvious. I urge everyone who hasn't already done so to take the time to read it.

Barack Obama's grand inaugural ceremony will take place today on the holiday memorializing King's birthday. Obama will always be linked in history to King because his election (and re-election) as America's first African-American president is, standing alone, an inspiring by-product of King's work on racial justice. But this symbolic link has another, less inspiring symbolic meaning: Obama's policies are a manifestation of exactly the militaristic mindset which King so eloquently denounced. Obama has always been fond of invoking King's phrase "fierce urgency of now", yet ironically, that is lifted from this anti-war speech, one that stands as a stinging repudiation of the continuous killing and violence Obama has spent the last four years unleashing on many countries around the world (Max Blumenthal suggested that Obama's second inaugural speech be entitled "I have a drone").

What I always found most impressive, most powerful, about King's April 4 speech is the connection he repeatedly made between American violence in the world and its national character. Endless war wasn't just destructive in its own right, but is something that ensures that America's "soul becomes totally poisoned", fosters "spiritual death", perpetuates the "malady within the American spirit", and elevates "the Western arrogance of feeling that it has everything to teach others and nothing to learn from them." In sum, to pursue endless war is "to worship the god of hate" and "bow before the altar of retaliation".

This is the overarching point that drives our current debates about war and militarism through today. The debasement of the national psyche, the callousness toward continuous killing, the belief that the US has not only the right but the duty to bring violence anywhere in the world that it wants: that is what lies at the heart of America's ongoing embrace of endless war. A rotted national soul does indeed enable leaders to wage endless war, but endless war also rots the national soul, exactly as King warned. At times this seems to be an inescapable, self-perpetuating cycle of degradation.

The way in which "America's soul is totally poisoned" is evident in virtually every debate over US policies of militarism. Over the weekend, several pro-war national security "experts" argued: "I'd pay closer attention to critics of drone strikes if they explained their recommended alternative." This is a commonly heard defense of Obama's drone assaults: I support drones - despite how they constantly kill innocent adults and children - because the alternative, "boots on the ground", is worse.

Those who argue this are literally incapable even of conceiving of an alternative in which the US stops killing anyone and everyone it wants in the world. They operate on the assumption that US violence is and should be inevitable, and the only cognizable debate is which weapon the US should use to carry out this killing (drones or "boots on the ground"?). Even though they have no idea who the US government is killing, they assume, with literally no evidence or basis, that those being killed are "terrorists" who want to attack the US and that therefore they - and anyone close to them - must be killed first. As Jonathan Schwarz noted on Sunday, they have literally embraced the same mindset as the Terrorists they claim to loathe: we must use violence and killing, even if it means we kill innocents, because we simply cannot conceive of any alternative.

Never once do they stop and wonder: why are there so many people in the world who want to attack the US? Never once do they do what King so bravely and rather subversively urged: "the true meaning and value of compassion and nonviolence" is it "helps us to see the enemy's point of view, to hear his questions, to know his assessment of ourselves". King explained: "from his view we may indeed see the basic weaknesses of our own condition, and if we are mature, we may learn and grow and profit from the wisdom of the brothers who are called the opposition." King thus urged the nation to "understand the arguments of those who are called enemy."

Adhering to King's prescription - "understanding the arguments of those who are called enemy" - would clearly reveal the obvious "alternative" to Obama's global assassination program: namely, ceasing the endless violence that is what drives so many people to want to bring violence to the US in return, combined with prosecutions of the handful of people who possess both the intent and capability to attack the US.

Arguing that "we must drone-bomb people in order to stop terrorism" is the equivalent of arguing that "we must continue to smoke cigarettes in order to stop lung cancer". As ample evidence proves, the so-called "solution" to Terrorism - endless violence and killing - is actually its primary cause. As the Yemeni blogger Noon Arabia put it this weekend after a series of multiple drones strikes on her country: "For those arguing effectiveness of drones, let me explain: civilians killed => animosity towards US = Qaeda members increase = Vicious [circle]!"

King made the same argument about Communists: that western militarism is not a solution to that ideology but is precisely what drives people to embrace it. He quoted a Vietnamese Buddhist leader who wrote that "each day the war goes on the hatred increases in the heart of the Vietnamese and in the hearts of those of humanitarian instinct"; that "the Americans are forcing even their friends into becoming their enemies"; and that "Americans, who calculate so carefully on the possibilities of military victory, do not realize that in the process they are incurring deep psychological and political defeat." That Buddhist leader, quoted King, warned that "the image of America will never again be the image of revolution, freedom and democracy, but the image of violence and militarism."

Citing the massive violence brought by the US to the world, King urged: "How can they trust us when now we . . . charge them with violence while we pour every new weapon of death into their land? Surely we must understand their feelings even if we do not condone their actions." Anticipating the predictable smears of him that he knew were coming from making this argument - from pointing out the US's own responsibility for the violence and extremism it claimed to be fighting - he said: "We must not call everyone a Communist or an appeaser who . . . recognizes that hate and hysteria are not the final answers to the problem of these turbulent days."

But a citizenry whose "soul becomes totally poisoned" by endless war is incapable of considering nonviolence as an alternative. It loses its capacity for empathy (to understand what motivates others' actions), for self-assessment (to acknowledge the role one's own actions play in perpetuating this violence), for rationality (to consider whether those being killed are actually implacable foes), and for communion (to see "the enemy" as anything more than dehumanized Others who must be extinguished). Thus do we hear - in the face of endless reports of dead children and innocent adults from US violence - this morally stunted defense: I can't think of an alternative other than boots on the ground. That's the mantra of a degraded citizenry trained to recite from a script of endless war.

Exactly the same mindset instantly arises if one points out the severe and escalating suffering from the sanctions regime which the US and its Nato allies are imposing on Iranians. The inevitable defense one will hear is identical to the drone defense: it's better than boots on the ground and all-out war.

Here we find the same stunted worldview. US aggression and belligerence toward Iran are and should be inevitable, and the only Serious debate is which weapons should be used to perpetuate it: sanctions or bombing? Questioning whether Iran is pursuing a bomb, or a negotiated settlement with its leaders, or containment if they do proliferate, are not even acknowledged as alternatives. It doesn't even enter the imagination. A citizenry that has been fed a steady diet of war and aggression and demonization is understandably incapable of even entertaining "alternatives" that do not involve causing the deaths of others, and of expressing nothing but pure callousness when confronted with the human suffering of the policies they support.

One of the best decisions the US ever made was to commemorate King's birthday as a national holiday. He's as close to a prophet as American history offers. But the distance between the veneration expressed for him and the principles he espoused seems to grow every year. When it comes to King's views on US militarism, nothing more potently illustrates that distance than the use of King's holiday to re-inaugurate the 44th president.